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ICS650-01
System Peripheral Clock Source
Description
The ICS650-01 is a low cost, low jitter, high
performance clock synthesizer for system
peripheral applications. Using analog/digital
Phase-Locked Loop (PLL) techniques, the device
accepts a parallel resonant 14.31818 MHz crystal
input to produce up to eight output clocks. The
device provides clocks for PCI, SCSI, Fast
Ethernet, Ethernet, USB, and AC97. The user can
select one of three USB frequencies, and also one
of three AC97 audio frequencies. The OE pin puts
all outputs into a high impedance state for board
level testing. All frequencies are generated with less
than one ppm error, meeting the demands of SCSI
and Ethernet clocking.
The ICS650 can be mask customized to produce
any frequencies from 1 to 150 MHz.
Block Diagram
Features
• Packaged in 20 pin tiny SSOP (QSOP)
• Operating VDD of 3.3V or 5V
• Less than one ppm synthesis error in all clocks
• Inexpensive 14.31818 MHz crystal or clock input
• Provides Ethernet and Fast Ethernet clocks
• Provides SCSI clocks
• Provides PCI clocks
• Selectable AC97 audio clock
• Selectable USB clock
• OE pin tri-states the outputs for testing
• Selectable frequencies on three clocks
• Duty cycle of 40/60
• Advanced, low power CMOS process
PSEL1:0
ASEL
USEL
14.31818 MHz
crystal
or clock
X1/ICLK
X2
2
Crystal
Oscillator
Clock
Synthesis
Circuitry
Output
Buffer
Output
Buffer
Output
Buffers
Output
Buffers
Output
Buffer
Output Enable (all outputs)
4
Processor Clocks
(Fast Ethernet,
SCSI, PCI )
Audio Clock
USB Clock
20 MHz
14.31818 MHz
MDS 650-01 C 1 Revision 092799 Printed 11/15/00
Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax
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ICS650-01
M
g
System Peripheral Clock Source
Pin Assignment
USEL
X2
X1/ICLK
VDD
VDD
GND
UCLK
20M
ACLK
PCLK4
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
PSEL1
PSEL0
PCLK2
PCLK3
VDD
ASEL
GND
14.318M
PCLK1
OE
Processor Clock (MHz)
PSEL1 PSEL0 PCLK1 PCLK2,3 PCLK4
0 0 25.00 50.00 18.75
0 M TEST TEST TEST
0 1 TEST TEST TEST
M 0 40.00 80.00 20.00
M M 33.3334 66.6667 25.00
M 1 20.00 40.00 25.00
1 0 20.00 33.3334 25.00
1 M 20.00 66.6667 25.00
1 1 Stops low all clocks except 20
Audio Clock (MHz)
ASEL ACLK
0 49.152
M 24.576
1 12.288
USB Clock (MHz)
USEL UCLK
012
M24
148
0 = connect directly to ground, 1 = connect directly
20 pin (150 mil) SSOP
to VDD, M=leave unconnected (floatin
)
Pin Descriptions
Pin # Name Type Description
1 USEL I UCLK Select pin. Determines frequency of USB clock per table above.
2 X2 XO Crystal connection. Connect to parallel mode 14.31818 MHz crystal. Leave open for clock.
3 X1/ICLK XI Crystal connection. Connect to parallel mode 14.31818 MHz crystal, or clock.
4 VDD P Connect to VDD. Must be same value as other VDD. Decouple with pin 6.
5 VDD P Connect to VDD. Must be same value as other VDD.
6 GND P Connect to ground.
7
8 20M O Fixed 20 MHz output for Ethernet. Only clock that runs when PSEL1=PSEL0=1.
9 ACLK O AC97 Audio clock output per table above.
10 PCLK4 O PCLK output number 4 per table above.
11 OE I Output Enable. Tri-states all outputs when low.
12 PCLK1 O PCLK output number 1 per table above.
13 14.318M O 14.31818 MHz buffered reference clock output.
14 GND P Connect to ground.
15 ASEL I ACLK Select pin. Determines frequency of Audio clock per table above.
16 VDD P Connect to VDD. Must be same value as other VDD. Decouple with pin 14.
17 PCLK3 O PCLK output number 3 per table above.
18 PCLK2 O PCLK output number 2 per table above.
19 PSEL0 I Processor Select pin #0. Determines frequencies on PCLKs 1-4 per table above.
20 PSEL1 I Processor Select pin #1. Determines frequencies on PCLKs 1-4 per table above.
UCLK O USB clock output per table above.
Key: I = Input; XO/XI = crystal connections; O = output; P = power supply connection
MDS 650-01 C 2 Revision 092799 Printed 11/15/00
Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax
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ICS650-01
)
System Peripheral Clock Source
Electrical Specifications
Parameter Conditions Minimum Typical Maximum Units
ABSOLUTE MAXIMUM RATINGS (note 1)
Supply voltage, VDD Referenced to GND 7 V
Inputs and Clock Outputs Referenced to GND -0.5 VDD+0.5 V
Ambient Operating Temperature 0 70 C
Soldering Temperature Max of 10 seconds 260 C
Storage temperature -65 150 C
DC CHARACTERISTICS (VDD = 3.3V or 5V unless noted
Operating Voltage, VDD 3.0 5.5 V
Input High Voltage, VIH Select inputs, OE 2 V
Input Low Voltage, VIL Select inputs, OE 0.8 V
Output High Voltage, VOH VDD=3.3V, IOH=-8mA 2.4 V
Output Low Voltage, VOL VDD=3.3V, IOL=8mA 0.4 V
Output High Voltage, VOH, VDD = 3.3 or 5V IOH=-8mA VDD-0.4 V
Operating Supply Current, IDD, at 5V No Load, note 2 50 mA
Operating Supply Current, IDD, at 3.3V No Load, note 2 30 mA
Short Circuit Current, VDD = 3.3 Each output ±50 mA
Input Capacitance Except X1 7 pF
AC CHARACTERISTICS (VDD = 3.3V or 5V unless noted)
Input Crystal or Clock Frequency 14.31818 MHz
Output Clocks Accuracy (synthesis error) All clocks 1 ppm
Output Clock Rise Time 0.8 to 2.0V 1.5 ns
Output Clock Fall Time 2.0 to 0.8V 1.5 ns
Output Clock Duty Cycle At VDD/2 40 50 60 %
One Sigma Jitter, except ACLK 75 ps
One Sigma Jitter, ACLK 170 ps
Absolute Clock Period Jitter PCLK, UCLK, 20M - 500 500 ps
Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged
exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability.
2. With all clocks at highest frequencies.
External Components
The ICS650 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1µF should be connected between VDD and GND (on pins 4 and 6, and pins 16 and 14),
as close to the chip as possible. A series termination resistor of 33Ω may be used for each clock output. The
14.31818 MHz crystal must be connected as close to the chip as possible. The crystal should be a
fundamental mode, parallel resonant, 30ppm or better (to meet the Ethernet specs). Crystal capacitors
should be connected from pins X1 to ground and X2 to ground. The value of these capacitors is given by
the following equation, where C
crystal with 16pF load capacitance, two 8pF caps should be used. If a clock input is used, drive it into X1
and leave X2 unconnected.
MDS 650-01 C 3 Revision 092799 Printed 11/15/00
Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax
is the crystal load capacitance: Crystal caps (pF) = (CL-12) x 2. So for a
L
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Package Outline and Package Dimensions
Q
EH
h x 45°
D
ICS650-01
System Peripheral Clock Source
20 pin SSOP
Millimeters
Symbol Min Max
A 1.55 1.73
b 0.203 0.305
c 0.190 0.254
D 8.560 8.740
E 3.810 4.000
H 5.840 6.200
e 0.635 BSC
h 0.410
L 0.406 0.889
Q 0.127 0.250
A
e
c
b
L
Ordering Information
Part/Order Number Marking Package Shipping Temperature
ICS650R-01 ICS650R-01 20 pin SSOP Tubes 0 to 70 C
ICS650R-01T ICS650R-01 20 pin SSOP Tape and Reel 0 to 70 C
ICS650R-01I ICS650R-01I 20 pin SSOP Tubes -40 to 85 C
ICS650R-01IT ICS650R-01I 20 pin SSOP Tape and Reel -40 to 85 C
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) assumes no responsibility for either its
use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is
intended for use in normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary
environmental requirements are not recommended without additional processing by ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does
not authorize or warrant any ICS product for use in life support devices or critical medical instruments.
MDS 650-01 C 4 Revision 092799 Printed 11/15/00
Integrated Circuit Systems • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • (408) 295-9818fax
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